Clean the affected marble well with marble cleaner and a soft cloth. Rinse well with clean water and allow the stone to dry.
Sprinkle a small amount of polishing powder onto the affected marble and spray with water to form a paste. Polishing powder is a very fine grit that when rubbed into the marble will grind its surface lightly, resulting in a polished finish.
Attach the wool buffing pad to the buffer and begin to buff the polishing powder into the marble. Work the buffer in a circular motion over the etch mark and surrounding area until the etched area matches the rest of the marble in polish and shine.
Rinse the marble well with clean water to remove the grit and dry with a soft cloth.